US6288696B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analog driver for led or similar display element
Assignee: Individual
•
Filing: 2000-03-21
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Granted: 2001-09-11
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Expires: 2020-03-21
Abstract
Abstract The analog driver for a display device which is controlled by current, such as an LED, includes a strobed analog input which charges a storage capacitor. The voltage across the storage capacitor is fed to the positive input of a comparator. The negative input of the comparator receives the voltage from a feedback resistor which is in series with the drive voltage, the drive FET (with a gate connected to the output of the comparator) and the light emitting device. Additionally, a reset FET is provided in parallel with the storage capacitor. Displays can be manufactured by a series of panels, each of the panels including an array of these drivers and light emitting devices, along with appropriate control circuitry.
Inventors
- 👤 Charles J Holloman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:24
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/04; G09G3/06; G09G3/12; G09G3/14; G09G3/20; G09G3/2007; G09G3/2011; G09G3/2085; G09G3/22; G09G3/30; G09G3/32; G09G2300/00; G09G2300/02; G09G2300/026; G09G2300/08; G09G2300/0809; G09G2300/0842; G09G2310/00; G09G2310/02; G09G2310/0264; G09G2310/0272; G09G3/004
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
83 words
A device for controlling current through a light emitting device in accordance with an analog informational signal, comprising: means for receiving the analog informational signal, means for charging a capacitor in accordance with the analog informational signal, and feedback means for controlling current through the light emitting device through a substantially continuous range thereby varying a brightness of the light emitting device through a substantially continuous range in response to changes in a voltage across said capacitor responsive to said analog informational signal.
Claim 2
Independent Claim
83 words
A device for controlling current through a light emitting device in accordance with an analog informational signal, comprising: means for receiving the analog informational signal, means for charging a capacitor in accordance with the analog informational signal, and feedback means for controlling current through the light emitting device through a substantially continuous range thereby varying a brightness of the light emitting device through a substantially continuous range in response to changes in a voltage across said capacitor responsive to said analog informational signal.
Claim 3
Dependent Claim
98 words
The device of claim 1 further including a first field effect transistor and a feedback resistor in series with said light emitting device and wherein said means for controlling current includes an operational amplifier with a positive input, a negative input and an output; wherein said positive input receives a voltage substantially equal to the voltage across said capacitor, said negative input receives a voltage substantially equal to the voltage across the feedback resistor and a gate of said first field effect transistor receives a voltage substantially equal to the voltage of said output of said operational amplifier.
Claim 4
Dependent Claim
17 words
The device of claim 2 further including a second field effect transistor for strobing said analog signal.
Claim 5
Dependent Claim
16 words
The device of claim 3 further including a third field effect transistor for discharging said capacitor.
Claim 6
Dependent Claim
31 words
The device of claim 4 further including a resistor to increase a leakage resistance of said operational amplifier, thereby adjusting an RC time constant and modifying a persistence of the device.
Claim 7
Independent Claim
113 words
A device for controlling current through a three color light emitting device in accordance with three respective analog informational signals, wherein said three color light emitting device includes three respective color circuits, the device comprising for each respective analog informational signal: means for receiving the respective analog informational signal, means for charging a capacitor in accordance with the respective analog informational signal, and feedback means for controlling current through the respective color circuit of light emitting device through a substantially continuous range thereby varying a brightness of the light emitting device through a substantially continuous range in response to changes in a voltage across said capacitor responsive to said respective analog informational signal.
Claim 8
Independent Claim
113 words
A device for controlling current through a three color light emitting device in accordance with three respective analog informational signals, wherein said three color light emitting device includes three respective color circuits, the device comprising for each respective analog informational signal: means for receiving the respective analog informational signal, means for charging a capacitor in accordance with the respective analog informational signal, and feedback means for controlling current through the respective color circuit of light emitting device through a substantially continuous range thereby varying a brightness of the light emitting device through a substantially continuous range in response to changes in a voltage across said capacitor responsive to said respective analog informational signal.
Claim 9
Dependent Claim
106 words
The device of claim 6 wherein the device for each respective analog signal further includes a first field effect transistor and a feedback resistor in series with said light emitting device and wherein said means for controlling current includes an operational amplifier with a positive input, a negative input and an output; wherein said positive input receives a voltage substantially equal to the voltage across said capacitor, said negative input receives a voltage substantially equal to the voltage across the feedback resistor and a gate of said first field effect transistor receives a voltage substantially equal to the voltage of said output of said operational amplifier.
Claim 10
Dependent Claim
26 words
The device of claim 7 wherein the device for each respective analog signal further includes a second field effect transistor for strobing said respective analog signal.
Claim 11
Dependent Claim
24 words
The device of claim 8 wherein the device for each respective analog signal further includes a third field effect transistor for discharging said capacitor.
Claim 12
Dependent Claim
39 words
The device of claim 9 wherein the device for each respective analog signal further includes a resistor to increase a leakage resistance of said operational amplifier, thereby adjusting an RC time constant and modifying a persistence of the device.
Claim 13
Dependent Claim
122 words
A panel including rows and columns of three color light emitting devices, each of said three color light emitting device responding in accordance with three respective analog informational signals, wherein each said three color light emitting device includes three respective color circuits, and comprising for each respective analog informational signal: means for receiving the respective analog informational signal, means for charging a capacitor in accordance with the respective analog informational signal, and feedback means for controlling current through the respective color circuit of light emitting device through a substantially continuous range thereby varying a brightness of the light emitting device through a substantially continuous range in response to changes in a voltage across said capacitor responsive to said respective analog informational signal.
Claim 14
Dependent Claim
122 words
A panel including rows and columns of three color light emitting devices, each of said three color light emitting device responding in accordance with three respective analog informational signals, wherein each said three color light emitting device includes three respective color circuits, and comprising for each respective analog informational signal: means for receiving the respective analog informational signal, means for charging a capacitor in accordance with the respective analog informational signal, and feedback means for controlling current through the respective color circuit of light emitting device through a substantially continuous range thereby varying a brightness of the light emitting device through a substantially continuous range in response to changes in a voltage across said capacitor responsive to said respective analog informational signal.
Claim 15
Dependent Claim
108 words
The panel of claim 11 wherein each light emitting device, further includes, for each respective analog signal, a first field effect transistor and a feedback resistor in series with said light emitting device and wherein said means for controlling current includes an operational amplifier with a positive input, a negative input and an output; wherein said positive input receives a voltage substantially equal to the voltage across said capacitor, said negative input receives a voltage substantially equal to the voltage across the feedback resistor and a gate of said first field effect transistor receives a voltage substantially equal to the voltage of said output of said operational amplifier.
Claim 16
Dependent Claim
28 words
The panel of claim 12 wherein each light emitting device, further includes, for each respective analog signal, a second field effect transistor for strobing said respective analog signal.
Claim 17
Dependent Claim
26 words
The panel of claim 13 wherein each light emitting device further includes, for each respective analog signal, a third field effect transistor for discharging said capacitor.
Claim 18
Dependent Claim
14 words
The panel of claim 14 wherein said rows are sequentially provided with input data.
Claim 19
Dependent Claim
44 words
The panel of claim 15 wherein each light emitting device further includes, for each respective analog signal, a resistor to increase a leakage resistance of each said respective operational amplifier, thereby adjusting an RC time constant and modifying a persistence of the respective device.
Claim 20
Dependent Claim
13 words
A display comprised of a plurality of the panels of claim 11 .
Claim 21
Dependent Claim
13 words
A display comprised of a plurality of the panels of claim 12 .
Claim 22
Dependent Claim
13 words
A display comprised of a plurality of the panels of claim 13 .
Claim 23
Dependent Claim
13 words
A display comprised of a plurality of the panels of claim 14 .
Claim 24
Dependent Claim
13 words
A display comprised of a plurality of the panels of claim 15 .
Claim 25
Dependent Claim
13 words
A display comprised of a plurality of the panels of claim 16 .
References Cited (Backward Citations)
US5184114A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-09-10 | 2005-03-12 | 2005-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-10 | 2009-03-12 | 2009-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-10 | 2013-03-12 | 2013-09-11 | $7700.00 | Window Closed / Lapsed |